This is untrue. I easily Downgraded from the official OTA 7.0 T-mobile update to the official T-Mobile 6.0.1 firmware without rooting and without tripping the Warranty Void flag and without tripping KNOX or anything else. And I am now back on the official T-mobile 6.0.1 firmware. Not rooted, not unlocked, etc. It does require completely wiping your phone as if you just got it from the store. But it was pretty easy and works fine. I am now just setting everything up again from scratch.

You will have to google it. There are many places where you can download the Official T-mobile firmware for the S7. Here are the details on what I did.

I easily Downgraded from the official OTA 7.0 T-mobile update to the official T-Mobile 6.0.1 firmware without rooting and without tripping the Warranty Void flag and without tripping KNOX or anything else. And I am now back on the official T-mobile 6.0.1 firmware. Not rooted, not unlocked, etc. It does require completely wiping your phone as if you just got it from the store. But it was pretty easy and works fine. I am now just setting everything up again from scratch.

Not sure if I am allowed to post the URLs. Here is the overview:

1. Backup anything you want on your phone manually to a computer like photos/videos, and with the Samsung Account phone backup online.

2. makes sure the phone is 80% or higher charge.

3. SD and Phone contents will be 100% lost and wiped. Samsung Pay will be cleared, fingerprints cleared, etc. Will be like store new.

4. Download the official T-mobile firmware for 6.0.1 "G930TUVU4APK1_G930TTMB4APK1_TMB.zip" , that is the file name for the T-mobile S7 (non-Edge) phone. Extract contents.

5. Download the latest ODIN app 3.12.3

6. If you have already used your phone on the computer, the drivers should already be in place.

7. Run ODIN.

8. Turn off your phone 100%, wait a few seconds to shutdown.

9. Hold Vol Down+Home+Power buttons for a few seconds. And when the screen comes on, let go. You should now see a screen warning about firmward. Press UP to continue to the Download Mode.

10. Now plug your phone into the PC with the USB cable. If drivers are in place, ODIN left side will say "added".

11. Press the button for BL, AP, CP, CSC. and load each file. For CSC choose the "HOME_CSC" file instead of the just CSC.

12. Press Start and wait. You will eventually get a greet box in ODIN. And when the phone reboots you can remove the USB cable.

13. You will now need to go into Recovery Mode to wipe the cache. Regardless of what the phone is now doing, likely a boot loop. Press and hold VOL UP+HOME+POWER to boot into Recovery Mode. You will have a back screen with a text menu. Navigate with vol keys and select with power button. Choose WIPE/FACTORY RESET. Followed by WIPE CACHE. Then choose the reboot phone option.

14. Phone will then have a white loading bar for a while. And should now boot to the factory new welcome screen where you pick the language and continue.

Overall pretty easy. Other than having to start from scratch. The only thing I am trying to figure out now, is how to get Android to stop asking me to upgrade again to 7.0!

I was able to reload and running the 6.0.1 a few day ago. I downloaded from SamMobile.com. Is this where you downloaded your firmware? Also after reloaded version 6.0.1, the T-Mobile update service keeps notifying me to download the latest version 7.0, do you have this pop-up if so how can you disable it?

As I said at the bottom of my last post, yes, I have the annoying notification about the 7.0 upgrade and it's driving me nuts. I too am looking for a way to get rid of that notification as it sits in the pull down notifications as well as at the top of the Settings section. Even though I have updates set to Manual. If I am not checking for an update, I don't want to see the notification. Annoying!

Here are some of the reasons why I like to go back to Marshmallow: the multi language auto-detectable texting was removed in Nougat which was really useful and smart, the camera selfie mode keeps accidentally switched on, the default font size is too small and mostly the battery drainage is really bad even after I did a clear cache!

I have had Nougat on the GS7e since they launched the Beta program last year. I never even knew about the auto-detectable multi language feature but do know some changes were made to the default keyboard and other "accessibility" features. For instance I use LastPass Password manager and after the upgrade to the Beta and again to the final version I had to go turn on the autofill feature in the accessibility menu as the upgrade kept turning it off. Sometimes I have noticed that when things disappear between OS versions it is because they took it from an default and made in an option (defaulted to off). Of course it could just be something the eliminated which has happened also, but keep in mind one of the big changes with Nougat is the move from TouchWiz to GraceUX. Touchwiz even if you liked it was notoriously intrusive and was the major source of lag on Samsung phones especially the Galaxy line which had the full Touchwiz. Samsung has really been trimming TouchWiz down over the last 2 years leading to it's retirement with Nougat and the move to GraceUX. Of course with all the positives there are always going to be negatives but with the performance benefits and smoother experience I think outways any 1 or 2 feature losses.

As for the battery issue and while this is purely anecdotal, even during the Beta (after they fixed the huge FB issue) I started having issues also but eventually found that if I removed FB Messenger the problem stopped. I got this from looking at my battery usage and noticed that FB Messenger was using resources and batter even though I never really used the program so deleted it and bingo no more issues in general.

I would google your language deal and see if there is any tips or something anyone discovered to either fix it or an app that will do the same thing. You can of course also send your issues/complaints to Samsung, I say Samsung because they develop the software and contrary to belief the carriers have nothing to do with updates other than testing them. But if you must just go to XDA and do some reading but again, warranty, support go out the window along with there is always a chance that during the process you can accidentally brick the phone.